The present invention relates to a program type automatic exposure controller for use in cameras, and more particularly, to such a controller which is selectively changeable to a plurality of program constants in a camera of the film surface reflection photometry type.
Recently, high sensitivity films have been developed and widely used and therefore information for a film sensitivity which is to be inputted into a camera covers an extensive range. Accordingly, in a program type automatic exposure camera, an exposure control by setting only one fixed program constant input thereinto over information for sensitivities of all kinds of films may be improperly conducted and hence a program constant requires changes in accordance with a variation in information for a film sensitivity.
In conventional program type automatic exposure controllers which are selectively changeable to a plurality of program constants, there have been well known such controllers that combinations of a plurality of program constants are previously stored and a photographer can timely select from the stored constant combination (U.S. Pat. Nos. 3,950,765 and 3,964,073) or in which the program constants are changeable based on information for a taking lens such as a focal length (Japanese Laid Open Patent Publication Nos. Sho 54-100724 and Sho 54-156533). However, a program type automatic exposure controller that can change program constants in response to information for a sensitivity of a film being used in a camera is not yet known.